Cartridge feed and firing mechanism



1944- H. DA COSTA v i 2,356,304

CARTRIDGE AND FIRING MECHANISM Filed Jan. 25, 1941 7 Sheets-Sheet l Aug. 22, 1944. H. DA COSTA 2,356,304

CARTRIDGE FEED AND FIRING MECHANISM Filed Jan. 25, 1941 7 Sheets-Sheet 2 -v 19. H. DA COSTA 2,356,304

I CARTRIDGE FEED AND FIRING MECHANISM Filed Jan. 25, 1941 '1 sheets-sheets A T S O C A D CARTRIDGE AND FIRING MECHANISM Filed Jan. 25, 1941 '7 Sheets-Sheet 4 Aug. 22, 1944. H, DA CO TA 2,356,304

CARTRIDGE FEED AND FIRING MECHANISM Filed Jan. 25, 1941 7 Sheets-Sheet5 Aug. 22, 19. H. DA cosTA CARTRIDGE FEED AND FIRING MECHANISM Filed Jan. 25, 1941 7 Sheets-Sheet 6 a Ahg. 22, 1944. H. DA cosTA I 2,356,304

CARTRIDGE FEED AND FIRING MECHANISM File d Jan. 25, 1941 7 Sheets-Sheet 7 Patented Aug. 22, 1944 UNITD STES PATENT Harry da Costa, Ilford, England, assignor to Ihe Plessey Company Limited, Ilford, Essex, England, a British company Application January 25, 1941, Serial No. 375,967 In Great Britain September 11, 1939 11 Claims.

This invention relates to feed and firing mechanisms for signal cartridges, cartridge flares, engine starters and like cartridge firing apparatus.

According to the present invention there is provided a feed and firing mechanism as aforesaid comprising a rotary cartridge magazine and the rotary driving means for the cartridge magazine and operating through a step-by-step transmission device to bring the cartridges successively into firing position, a firing hammer and means operated by the rotary driving means for actuating the firing hammer between steps in the movement of the magazine. The stepby-step transmission device for the magazine preferably comprises a Geneva drive and the firing hammer is conveniently spring-loaded for movement to fire a cartridge and is withdrawn against the action of the spring by a rotary cam driven by the said rotary driving means. A feature of the invention consists in that the camis directly interconnected with the driving element of the step-by-step transmission device for the magazine for rotation therewith. The cam and the step-by-step transmission device are preferably so inter-related that the firing hammer is released by the cam to fire a cartridge at the completion of a feeding movement of the magazine.

In one form the rotary driving means comprises a ratchet device for rotating the driving element of the step-by-step transmission device by successive identical operations for firing cartridges in succession. This ratchet device conveniently comprises a ratchet wheel which is rigid with the driving element of the step-bystep transmission device and a rotatably mounted operating member having a pawl engaging with the ratchet wheel. In this form the mechanism is suitable for manual operation by means of a cable secured to the operating member for turning it against the action of a spring.

In another form the rotary. driving means comprises an electric motor and means is provided automatically to open the motor circuit on a firing movement of the hammer taking place. For the control of the motor there is preferably provided normally closed electric contacts in the motor circuit, an operating member for the contacts and an electro-magnet energised through a control switch in the motor circuit for moving the operating member into a position for opening the contacts, which operating motor is connected to the firing hammer so as to be moved thereby to open the contacts on a firing movement of the hammer taking place.

A further feature of the mechanism consists in that a frame member carrying the magazine has a charging opening with a movable cover and this cover is coupled to means for lifting the firing hammer clear of the cartridges to permit rotation of the magazine for re-loading. The magazine is preferably coupled to the driven member of the step-by-step transmission device through an over-ridable dog-clutch for the purpose of permitting rotation of the magazine for re-loading and to properly position the magazine with respect to the driven member of the stepby-step transmission device for rotation of the magazine by the rotary driving means in firing the cartridges.

A further feature of the mechanism consists in that the magazine comprises a plurality of cartridge chambers assembled on arotatable carrier and secured thereon by means of a, strap passing around the assembly of cartridge chambers.

According to a further feature of the invention there is provided a muzzle movable lengthwise in line with a cartridge chamber of the magazine in the firing position and spring means for urging the muzzle into engagement with the end of the cartridge chamber. Another feature of the invention consists in the provision of a muzzle which has an enlarged bore terminating with a neck of less diameter at its inner end for the purpose of producing a gaseous back pressure operative on the muzzle pressing it against the end of the cartridge chamber toeifect a seal therewith when a cartridge is fired.

One specific construction of a gun for firing recognition signal cartridges and embodying the invention is shown by way of example in the accompanying drawings, in which:

Figure 1 is a plan of the gun constructed for manual operation;

Figure 2 is an end elevation partly'in section on line 2-2 of Figure 1;

Figure 3 is a section on line 33 of.Figure 1;

Figure 4 is a detail view and is a section on line 4-4 of Figure 3;

Figure 5 is a section on line 55 of Figure 1;

Figure 6 is a section on the line 66 of Figure 1;

Figure 7 is an elevation partly insection on line 1-1 of Figure 1;

Figure 8 is a detail view of the dog-clutch;

Figure 9 is an elevation partly in section'show- OVer ridabIe ing a modification for electrical operation, and

Figure 10 is a circuit diagram.

Referring to Figures 1 to 8 of the drawings, the rotary magazine is carried by a rigid frame formed of a front plate I and a rear plate II, interconnected by stays I2, I3 and I4, the stay I4 constituting a spindle on which the magazine rotates. The magazine comprises two spiders I5 and I6 connected by bars I1, the spiders being formed with a scalloped periphery to receive six cartridge chambers I8. These cartridge chambers are formed with a pair of ribs I3 at each end in which the spiders are located. A metal strap passes around the assembly of cartridge chambers and serves to hold them secured to the spiders. The strap 26 is placed under tension by means of studs 2| passing through stiffening strips 22 and the strap 20 and screw-threaded in the bars I1. For the firing position each cartridge chamber I8 is positioned in line with an opening in' the front plate II] in which is located a muzzle 23 carried also in an opening in an outer plate 24 mounted on the plate Ill. The muzzle is movable lengthwise in the openings in the plates I0 and 24 and is pressed inwardly by means of springs I23 bearing on a thrust plate I24 resting against a flange 25 on the muzzle. The inward movement of the muzzle is restricted by the flange 25 coming to rest on the plate I0. diameter than the cartridgechamber' and is formed with a neck I25 of smaller diameter and conveniently of the same diameter as the car tridge chamber. Thus when a cartridge is fired a gaseous back pressure is produced on the muzzle serving to press it against the end of the cartridge chamber to effect ase al.

On the spider I6 there is secured an index plate 26 formed with a plurality of equally spaced re-.

cesses 21. A bearing sleeve 28 has a shoulder 29 bearing on the index plate 26 and is secured to the spider I6 by means of a nut 30 screw-threaded on this sleeve. A member 3| is rotatably mounted on the sleeve 28 and has recesses 32 spaced in the same way and opposite to the recesses 21 in the index plate 26. Balls 33 carried in the recesses 32 are pressed outwardly by means of springs '34 to engage in the recesses 21 so as to provide an over-ridable ball clutch or index device giving a definite location of the magazinewith respect to the member 3| so long as the balls 33 remain engaged in the recesses 21 of the index plate.

The member 3| constitutes the driven member of a Geneva drive for the magazine and is formed with six equally spaced radial slots 35, as Shown more particularly in Figures 5 and 6. The driving member of this Geneva drive consists of a disc 36 carried on a rotatably mounted spindle 31 offset from the stay I4 and'having three equally spaced laterally extending pins .38 arranged to enter into the slots 35. The driving and driven elements of the Geneva drive are carried in recesses 39 and 40 respectively in the rear plate I I.

The driving element 36 of the Geneva drive is formed with a cam face 4| co-operating with a nose 42 on a firing hammer 43. Thefiring hammer 43 is mounted on a pivot pin 44 for movement The muzzle is of larger internal CPI '- magazine commences to move.

The cam face 4| has three equally spaced projections 52, each consisting of a gradual rise 53 at the leading side and a steep drop 54 at the trailing side of the projection.

In the normal at-rest position of the mechanism the nose 42 of the firing hammer lies immediately behind the steep drop 54 of a cam projection, as shown in Figure '1, so that the firing pin 46 is in the fully projected position. Also, two pins 38 of the Geneva drive are engaged in slots 35, as shown in Figure 6. For operating the mechanism the spindle 31 is turned through onethird of a revolution. During this movement the firing hammer i raised by the sloping surface 53 of the next cam projection 52. The spindle 31 is coupled to the magazine through a 2 to 1 gearratio by means of the Geneva drive so that the rotation of the spindle 31 turns the magazine through one-sixth of a revolution to bring the next cartridge chamber into line with the firing.

point. When this position is reached the nose of. 'the firing hammer passes over the projection 52:

of the cam and the hammer is projected for wardly by the spring 48 to fire the cartridge. The:

" Geneva drive is such that the rate of movement of.

the magazine is zero, or substantially zero, at the: position of a cartridge chamber for firing, so that; when -a firing operation is initiated the firing; point 46 is freed from the cartridge before the: In place of the- Geneva drive shown in the drawings other forms: of Geneva drive may be employed to provide the step-by-step transmission, for instance, a Geneva 7 stop motion may be provided having interfitting and sliding stop surfaces, especially should it be desired to increase the rest period of the magazine 7 between each feeding step.

The ends of the cartridge chambers I8 ar masked by the rear plate I I which has an opening for re-loading purposes, this opening coinciding with one of the cartridge chambers I8, when another of them is in the firing position. The

opening is provided with a cover 56 which'is carried on a spindle 51 rotatable inva bore 58 in the 1 rear plate I I, as shownin Figures 3 and 4. The

spindle is retained in the bore 58 by means of a stud 6| in the rear plate and engaging behind a shoulder 62 of the spindle. The spindle is formed with a flat 59 with which engages a spring-loaded plunger 60 serving resiliently to retain the cover I hammer when in its firing position. When the in a cross-slot 45 in the rear plate I The firing hammer 43 is urged towards the firing position,

K cover is lifted for re-loading purposes the spindle 51 is turned so as to lift the hammer 43 and thus retract the firing point 46 to permit the magazine to be rotated without the cartridge fouling the firing point. The over-ridable dog clutch constituted by the index plate 26of the engaging balls 33 transmits the drive to the magazine without slipping. For loading purposes, however, the magazine is rotated without operating the firing mechanism by causing the index plate 26 to override the balls 33 but is subsequently set in correct relationship with the'cam surface 4| by the re engagement. of the balls 33 with the recesses of the index plate. i

p The spindle 31iis rotatably mounted in a sleeve 64 carried by the rear plate II.

tends beyond the outer surface of the rear plate I and constitutes a bearing for a rotatable disclike operating member 65. At the outer side of this operating member a ratchet Wheel 66 is secured on the spindle "31. The ratchet wheel 66' The sleeve ex- 'hasthree equally 'spaced teethBI co-operating with-a pawl 68 pivoted on the operating member and urged towards the ratchet-wheel by means of a spring 69 interposedbetween the pawl and an abutment 10 on theoperating member. The operating member is arranged to be turned by means of a cable H against the action of a coiled return spring 12, this spring being anchored at one end over an end of the abutment l9 and at the other end on a stud 13 secured in the rear plate H. The stud I3 projects through an arcuate slot 14 inthe operating member 85,-the length of this slot determining the limit of movement of the operating member through a. distance somewhat greater than-one-third of a revolution. A fixed cover 15 for the operating member is located by passing over theouter end of the spindle 31 and is fixed inposition on the stud 13. Thus, for operation of the mechanism the cable .'H is pulled to turn the operating member so that by means of the pawl 68 and ratchet wheel 66 the spindle 37 is turned through one-third of a revolution. The

cable ll being allowed to return the operating member 65 falls back under the action of the spring 12 preparatory to a subsequent similar operation of the mechanism in which the pawl 68'engages the next tooth 6'! and the ratchet wheel 66.

In the modified arrangement shown in Figures 9 and 10, the mechanism is operated electrically. In this case a contact operating member consisting of an arm 16 is pivoted at 11 on the heel of the firing hammer 43. This operating member constitutes an armature for an electro-magnet l8 and is normally held away from the magnet by a spring 19. The firing hammer is propelled by a tension spring 80 connected between the heel 5| and an anchorage 8| on the rear plate I I. The arm 16 is formed with a nose 82 for operating a pair of contacts 83, 84.

The driving member 38 is in this case formed as a gear-wheel but it is integral, as in the preceding construction, with the cam face 4|. This gear-wheel is in mesh with a pinion indicated at 85 carried on a spindle 88 which is coupled by means of a worm and wormwheel indicated at 81 with the spindle 88 of an electric motor indicated at 89. As shown in Figure 10, the motor 89 is connected in series with the contacts 83 and 84 and a control switch 99 across a battery 9|, and the electro-magnet 18 is connected in parallel with the motor 89 and the contacts.

In the normal at-rest position the parts are located in the manner shown in Figure 9 in which the contacts 83 and 84 are closed. For operation of the mechanism the control switch 99 is closed, thus completing a circuit through the electro-magnet l8 and through the motor 89. On the magnet being energised the arm 78 is attracted and the nose 82 is engaged on the end of the contact 83. The motor rotates the driven element 36 of the Geneva drive so that the cam surface lifts the firing hammer 43. The arm 16 is in consequence moved lengthwise so that the nose 82 is engaged behind the contact 83. By the firing movement of the hammer the arm 16 is displaced and as the nose B2 is engaged behind the contact 83, this contact is separated from the co-operating contact 84, as shown in Figure 10, thus opening the circuit of the motor 89. The electro-magnet 18 remains energised while the control switch 98 remains closed. When the control switch is opened to de-energise the electro-magnet 18 the arm 16 is retracted by the spring 19 and the contacts 83 and 84 are again closed in readiness for asubsequent firing operation. It will be'seen therefore that the control switch 99 has to be closed for each firing operation and opened before the-next firing operation can be initiated.

Whereas the invention for example in the specific form hereinbefore described with reference to the accompanying drawings, is especially adapted for firing signal cartridges, flares or the like, it is also applicable for firing cartridges for other purposes, including the production of high gas pressures for pressure-operated devices, such as starters for internal-combustion engines.

I claim:

1. A feed and firing mechanism for signal and like cartridge-firing apparatus comprising in combination a frame,- a cartridge-magazine having a plurality of (cartridge-chambers and rotatable about a fixed axis in said frame, a driving spindle, a driving member carried thereby and comprising the driving element of a Geneva transmission device, the driven element of which is mounted to rotate with the cartridge-magazine about an axis spaced from that of the driving spindle, a firing hammer spring-loaded towards the firing position, a rotary hammer-actuating cam-member also rotatable on said driving spindle and having a plurality of cams so proportioned in number to the gear ratio of the Geneva transmission device that the firing hammer will operate successively on cartridges contained in the said cartridge chambers as the same are brought into the firing position and while the cartridge-magazine is held stationary by the transmission device, and driving means for the driving spindle.

2. A feed and firing mechanism according to claim 1, in which the driving means for the driving spindle comprises a motor for imparting continuous rotation to the spindle in combination with means to control the operation of the motor.

3. A feed and firing mechanism according to claim 1 in which the driving means for the driving spindle comprises a driving spring, a pawl and ratchet mechanism coupling the driving spring to the driving spindle in order to impart under the action of the spring a uni-directional drive to the spindle, and rotatable winding means to load the spring and to impart this load through the spring to the pawl and ratchet device to turn the driving spindle.

4. A feed and firing mechanism according to claim 1 in which the driving means for the driving spindle comprises a ratchet wheel rigid with the driving spindle, a ratchet carrying member rotatable about the axis of the driving spindle, a driving spring, one end of which is anchored to the ratchet carrying member, and the other of which is anchored to a fixed stop, and means to turn the ratchet carrying member to load the spring.

5. A feed and firing mechanism according to claim 1 in which the driving means for the driving spindle comprises a ratchet wheel rigid with the driving spindle, a ratchet carrying member rotatable about the axis of the driving spindle, a driving spring, one end of which is anchored to the ratchet carrying member, and the other end of which is anchored to a fixed stop, means to turn the ratchet carrying member to load the spring, and means to limit the degree of angular movement imparted to the ratchet carrying member during the loading of the spring.

6. A feed and firing mechanism according to claim 1 in which the driving means for the driving spindle comprises an electric motor carried on the said frame, and means coupling the electric motor to the driving member of the Geneva transmission mechanism.

7. A feed and firing mechanism according to claim 1 in which the driving means for the driving spindle comprises an electric motor carried on the same frame, means couplingthe electric motor to the driving member of the Geneva transmission mechanism, a motor energizing circuit, a normally closed circuit interrupting switch in the motor energizing circuit, and means operatively connecting the firing hammer with said interrupting switch to open the circuit by a firing movement of the hammer.

8. A feed and firing mechanism according to claim 1 in which the driving means for the driving spindle comprises an electric motor carried on the said frame, means coupling the electric motor to the driving member of the Geneva transmission mechanism, a motor energizing circuit, a normally c10sed circuit interrupting switch in the motor energizing circuit, and means operatively connecting the firing hammer with said interrupting switch, said operative connection comprising an electromagnet, an armature therefor pivoted to the hammer to swing into and out from engagement with the interrupting switch, an energizing circuit for the electromagnet, and a switch for controlling the last-named energizing circuit. 7

9. A feed and firing mechanism according to claim 1 having an opening in the frame for charging the magazine chambers, a movable cover for said opening and mounted independently of the firing hammer, and means coupled to said cover for lifting the firing hammer clear of the cartridges in the magazine when the cover is opened.

10. A feed and firing mechanism according to claim 1 having an opening in the frame for charging the magazine chambers, a movable cover for said opening and mounted independen'tly of the firing hammer, means coupled to said cover for lifting the firing hammer clear of the cartridges in the magazine when the cover is opened, and an overridable positioning clutch between the Geneva transmission device and the rotary magazine.

11. A feed and firing mechanism according to claim 1 in which the cartridge chambers are assembled on a carrier formed with radial recesses in which portions of the peripheries of the chambers are received, in combination with a strap passing round the chambers to secure them in the carrier recesses.

HARRY DA COSTA. 

